1. Field of the Invention
The present invention relates to a clutch hydraulic system for a vehicle and to hydraulic system.
2. Description of Background Art
As a clutch hydraulic system for a vehicle and hydraulic system according to the existing art, a system is known that includes two hydraulic systems for connecting and disconnecting an automotive clutch. See, for example, Japanese Patent Laid-open No. Hei 8-296670.
FIG. 1 of Japanese Patent Laid-open No. Hei 8-296670 will be described as follows.
Of the two hydraulic systems, one is a system for operating a master cylinder 5 by a clutch pedal 7, and the other is a system for operating a sub master cylinder 12 by a power cylinder 14. The master cylinder 5 and the sub master cylinder 12 are connected to a release cylinder 3 through a three-port valve 20, and the release cylinder 3 is connected to a clutch 1.
The master cylinder 5 is fitted with oil supplier 6, and the sub master cylinder 12 is fitted with oil supplier 13.
While the oil suppliers (reservoir tanks) 6, 13 are provided respectively in the two hydraulic systems mentioned above, it is necessary to provide the oil suppliers 6, 13 at the highest position in the hydraulic system for the purpose of supplying each of the hydraulic systems with oil, so that a plurality of layout spaces must be secured at the highest site in the hydraulic system for the purpose of arranging the plurality of oil suppliers 6, 13, resulting in that the degree of freedom in designing a clutch control system is reduced. In addition, the arrangement of the two oil suppliers 6, 13 leads to a rise in cost.
Furthermore, since the oil passages of the two systems are changed over by the three-port valve 20, the need to disconnect the clutch 1 by the clutch pedal 7 in the condition where, for example, the clutch 1 is disconnected by the power cylinder 14 cannot be fulfilled. In other words, the two hydraulic systems cannot be operated independently.